Automotive milling machine, as well as method for steering an automotive milling machine

ABSTRACT

In an automotive milling machine, with a machine frame with longitudinal axis, with a chassis with wheels or tracked travelling drive units which support the machine frame, with a controller for the travelling, steering and milling operation, with a height-adjustable working drum, with a slewable last or single transport conveyor of specified length arranged in front of or behind the working drum as seen in the direction of travel of the milling machine, where the transport conveyor is, as a minimum, slewable sideways about an essentially vertical first axis under a slewing angle, it is provided for the following features to be achieved: the controller comprises a detection and control system which, as a minimum, detects the steering angle of the steering controller for the chassis or, as a minimum, the steering angle of the steering controller and the distance travelled or the travel speed, and controls the slewing angle of the transport conveyor in accordance with this no less than one parameter.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to an automotive milling machine, as well as to amethod for steering an automotive milling machine.

2. Description of the Prior Art

The automotive milling machine, in particular road milling machine orsurface miner, comprises a machine frame with longitudinal axis, achassis with wheels or tracked travelling drive units supporting themachine frame, as well as a controller for the travelling, steering andmilling operation and a height-adjustable working drum. A slewable lastor single transport conveyor of specified length is arranged in front ofor behind the working drum as seen in the direction of travel of themilling machine, where said transport conveyor is, as a minimum,slewable sideways about an essentially vertical first axis under aslewing angle.

The milling machine comprises a controller for the travelling andmilling operation, as well as a working drum for the milling of, forexample, a road pavement. A transport conveyor device comprising no lessthan one transport conveyor is located in front of or behind the workingdrum as seen in the direction of travel. The last or single transportconveyor of the transport conveyor device as seen in the direction oftransport may be slewed sideways, relative to the longitudinal axis ofthe milling machine, under a specifiable slewing angle to the left orright and may be adjustable in height via a specifiable elevation angle.The transport conveyor device comprises a discharge end at which themilled material is discharged onto the loading surface of a transportvehicle via a flight path in the form of a parabolic trajectory that isattributable to the conveying speed and the elevation angle.

In practical operation of such a milling machine, problems caused by thewidely projecting transport conveyor arise when steering the millingmachine during operation and when relocating the milling machine to adifferent position.

With a front-loading milling machine, for example, the milled materialis discharged towards the front onto the transport vehicle drivingahead. The operator of the milling machine needs to signal to thevehicle driver of the transport vehicle as to when the transport vehicleis to continue moving forward. This leads to problems because theoperator basically needs to concentrate on the milling process and atthe same time needs to avoid a collision with the transport vehicledriving ahead.

An additional problem lies in the fact that the operator of the millingmachine also needs to deal with loading the loading surface by adjustingthe slewing angle, elevation angle and conveying speed of the last orsingle transport conveyor of the transport conveyor device as seen inthe direction of transport and is thus distracted from his actual task,which consists in carrying out the milling process. A correction of theslewing angle may be required, for example, when altering the directionof travel of the milling machine.

In case of a rearward-loading milling machine, problems also arise incoordinating the milling machine with the transport vehicle especiallyas the transport vehicle needs to drive behind the milling machine inreverse travel. An even higher level of stress results for the operatorof the milling machine as he needs to control the milling process inforward travel on the one hand, and needs to monitor loading of thetransport vehicle behind the milling machine as seen in the direction oftravel, needs to control the slewing angle, elevation angle and/orconveying speed of the transport conveyor device, and needs tocommunicate the necessary information to the vehicle driver on theother.

When relocating the automotive milling machine to a different position,the operator of the milling machine must make sure that the widelyprojecting transport conveyor does not collide with any lateralobstacles, such as poles, along a track in particular when corneringnarrow bends. The transport conveyor may be longer than the actualmilling machine and usually measures approx. 5 m to approx. 8 m inlength.

SUMMARY OF THE INVENTION

It is therefore the object of the invention to create an automotivemilling machine, as well as a method for steering the milling machine,in which the operator of the road milling machine can drive the millingmachine during the milling operation or during repositioning of themilling machine without needing to continuously correct the slewingangle of the transport conveyor when cornering, and can do soindependent of the direction of travel of the milling machine and thearrangement of the transport conveyor in front of or behind the millingmachine as seen in the direction of travel.

The invention advantageously provides that the controller comprises adetection and control system which, as a minimum, detects the steeringangle of the steering controller for the chassis or, as a minimum, thesteering angle of the steering controller and the distance travelled orthe travel speed, and controls the slewing angle of the transportconveyor in accordance with this no less than one parameter. Thesteering angle enables determination of the current radius of curvaturewhen cornering, and the current radius of curvature enablesdetermination of any necessary adjustment of the slewing angle.

Such automatic control of the slewing angle enables the operator of themilling machine to concentrate on the milling operation and ontravelling along a specified milling track, or to relocate the millingmachine to a different position whatsoever respectively, without itbeing necessary to continuously correct the adjusted slewing angle ofthe transport conveyor. The milling machine can thus be moved in thedirection of travel similar to a vehicle with a towed single-axletrailer. In the milling operation, it can also be achieved in this waythat the end of the transport conveyor or the point of discharge isalways maintained along the centre line of the trajectory of the millingtrack travelled or along an equidistant to the centre line or within atrack of the automotive milling machine. The operator is relieved inthat he is not required to continuously concern himself with adjustingthe slewing angle of the transport conveyor in particular when drivingin bends.

It is preferably intended for the detection and control system tocontinuously control the slewing angle of the transport conveyorautomatically in such a way that the slewable transport conveyor assumesa slewing angle in each steering situation during forward travel orreverse travel which essentially corresponds to the slewing angle of thelongitudinal axis of a slewable fictitious single-axle trailerarticulated at the first axis when in forward travel.

As a result, the controller can specify a slewing behaviour for thetransport conveyor when cornering, both in forward travel and in reversetravel, which corresponds to that of a fictitious single-axle trailerwhen in forward travel. The operator can thus also drive the millingmachine in reverse mode without the transport conveyor behaving similarto a trailer during reverse travel.

In accordance with a further development, it is intended for thedetection and control system to specify a slewing angle for the slewabletransport conveyor which essentially corresponds to the slewing angle ofthe longitudinal axis of a slewable trailer articulated at the firstaxis when in forward travel, where the position of the centre ofrotation about the axis of the fictitious trailer is selectable inlongitudinal direction.

When mentally substituting the transport conveyor with a trailer ofcorresponding length, the position of the centre of rotation of thefictitious trailer, in a trailer with a single axle, is where the wheelaxle crosses the longitudinal axis of the trailer. The position of thecentre of rotation may be specified by means of the controller in thatthe distance of the centre of rotation from the first vertical axis isentered into the controller.

The centre of rotation may exhibit a distance from the first axisranging between one third and the entire length of the slewabletransport conveyor or the length to the point of discharge, preferablyranging between 40% and 60% of the entire length. Setting the centre ofrotation to a value of approx. 50% of the length L is of advantage whenrepositioning the milling machine as the lateral swinging-out of thetransport conveyor is then minimized.

For the milling operation, a value deviating therefrom could also beused. It is also possible for the operator to alter the position of thecentre of rotation while driving or in accordance with the type ofcornering (such as, for example, driving in a roundabout or turning offat right angles).

The controller may also compute the slewing angle to be specified fromthe currently specified steering angle (or a steering angle averagedover a specific travel distance respectively) and the constant geometricconditions in that the currently driven bend radius is computed from thesteering angle, and the slewing angle of the transport conveyor (in theform of a secant) relative to the longitudinal axis of the millingmachine in the current circular track is computed from the bend radius.

The interrelation between the bend radius r and length L of thetransport conveyor follows, for example, from the followingrelationship:L=2r sin(α/2),where α is the angle between the radii which are pointed at the ends oflength L. The slewing angle is then α/2 in relation to the longitudinalaxis of the milling machine. It is therefore possible to specify aslewing angle of α/2 with a variation range of up to ±30%. Length L mayalso refer, above and beyond the length of the transport conveyor, tothe length of the transport conveyor up to the point of impingement ofthe milled material on a loading surface of a transport vehicle.

It is preferably intended for the detection and control system tocontinuously control the slewing angle of the slewable transportconveyor automatically in such a way that the slewable transportconveyor assumes a specified slewing angle in each steering situationduring forward travel or reverse travel in which the end of thetransport conveyor is essentially guided along the centre line or anequidistant to the centre line of the track previously travelled over oryet to be travelled over.

In one particularly preferred further development, it is intended forthe transport conveyor to be slewable, under a specified elevationangle, about a second axis orthogonal to the first axis, in whicharrangement the transport conveyor discharges the milled material ontothe loading surface of a transport vehicle at a specified conveyingspeed, and the detection and control system continuously locates theposition of the loading surface and/or of the transport conveyor andperforms a continuous control of the elevation angle of the transportconveyor and/or a continuous speed control of the conveying speed inorder to always maintain a point of impingement on the loading surfacewithin said loading surface or, as a minimum, along the longitudinalmedian plane of the loading surface or along the centre line of thetrack previously travelled over or yet to be travelled over.

An automatic discharging procedure is thus realized which ensuresautomatic coordination of the discharging procedure with the movement ofthe milling machine and of the transport vehicle even when cornering. Inthis arrangement, the slewing angle of the transport conveyor device iscontrolled in accordance with the steering angle of the automotivemilling machine.

It is preferably intended for the detection and control system tocomprise no less than one detector which directly or indirectly detectsthe specified steering angle of the steering controller for the chassis,or the steering angle and the distance travelled or travel speed, and tocomprise additional detectors which directly or indirectly detect theslewing angle and the elevation angle.

An advantageous embodiment provides for the detection and control systemto comprise a distance measurement device which can be used to detectthe distance to a transport vehicle following in the conveying directionof the transport conveyor, wherein the detection and control systemgenerates start/stop signals for the transport vehicle which arediscernible by, preferably visible to the vehicle driver of thetransport vehicle.

In this arrangement, it may be intended for a distance rangeprogrammable or importable by means of teach-in to be enterable into thedetection and control system, said distance range being shorter than themaximum length of the loading surface of the particular transportvehicle, with the start or stop signal being controllable in accordancewith the distance measured when leaving the specified distance range.

Movement control signals for the transport vehicle have been describedin principle in DE 10 2009 041 842 A1.

The method according to the invention relates to a method for steeringan automotive milling machine, in particular road milling machine orsurface miner, along a specified track, said automotive milling machinecomprising a controller for the travelling, steering and millingoperation. The milling machine with longitudinal axis is supported by asteerable chassis with wheels or tracked travelling drive units, wherethe milled material removed by a working drum is transported away, inthe milling operation, by a transport conveyor arranged in front of orbehind the milling machine as seen in the direction of travel of themilling machine. The last or single transport conveyor can be slewedsideways. As a minimum, the steering angle of the steering controllerfor the chassis, or, as a minimum, the steering angle of the steeringcontroller and the distance travelled or the travel speed are detected,and the slewing angle of the transport conveyor is controlled inaccordance with this no less than one parameter.

In this arrangement, the slewing angle of the transport conveyor may becontinuously controlled automatically in such a way that the slewabletransport conveyor assumes a specified slewing angle in each steeringsituation during forward travel or reverse travel which essentiallycorresponds to the slewing angle of the longitudinal axis of afictitious trailer slewable about the first axis when in forward travel.

It is preferably intended for the slewing angle of the slewabletransport conveyor to be continuously controlled automatically in such away that the specified slewing angle essentially corresponds to theslewing angle of the longitudinal axis of a fictitious trailer slewableabout the first axis when in forward travel, where the position of thecentre of rotation of the trailer along the longitudinal axis of thetransport conveyor can be selected freely in order to compute and adjusta current slewing angle.

Additional advantageous features can be inferred from the description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, embodiments of the invention are explained in moredetail with reference to the drawings.

The following is shown:

FIG. 1 a rearward-loading road milling machine,

FIG. 2 a front-loading road milling machine, and

FIG. 3 a schematic illustration of controlling the slewing angle inaccordance with the steering angle in a road milling machine accordingto FIG. 1

DETAILED DESCRIPTION

The following description relates to automotive milling machines,namely, in particular to road milling machines and also to surfaceminers.

FIG. 1 depicts a rearward-loading milling machine 1 b as an example inwhich the transport vehicle 10 is travelling behind the milling machinein reverse travel mode.

Provided that sufficient space is available on the side next to themilling machine 1 a, 1 b, the transport vehicle 10 may also be movednext to the milling machine 1 in forward travel.

FIG. 2 shows a milling machine using as an example a front-loading roadmilling machine 1 a. The road construction machine 1 comprises a machineframe 2 which is supported by a chassis 4 comprising, for example,tracked travelling drive units or wheels, said chassis 4 being connectedto the machine frame 2 via no less than three height adjustment devicesin the form of lifting columns 5. As can be inferred from FIG. 2, fourlifting columns 5 are intended for the embodiment which can be used tobring the machine frame 2 into a specifiable plane extending preferablyparallel to the road surface 6 which supports the tracked travellingdrive units of the chassis 4.

The road milling machine shown in FIG. 2 comprises, in longitudinaldirection of the milling machine 1 a, a working drum 22 between thetracked travelling drive units of the chassis 4.

The working drum may be adjustable in height via the lifting columns 5supporting the machine frame 2 or relative to the machine frame 2.

The milling machines 1 a, 1 b may comprise tracked travelling driveunits and/or wheels. The tracked travelling drive units and/or wheelsmay also be referred to as ground engaging units or as running gears.

Other designs of a milling machine 1 b may exhibit the working drum 22,for example, at the height of the rear tracked travelling drive units orwheels of the chassis 4, as illustrated in FIG. 1.

The milling machines 1 a, 1 b may comprise a single steerable axle as asteerable axle, or may comprise a steerable front axle in combinationwith no less than one rear steerable wheeled or tracked travelling driveunit.

A transport conveyor device with no less than one transport conveyor11,12 for transporting away the milled material may also be arranged atthe front end 7 or at the rear end 8 of the milling machine 1 a, 1 b.

The directions of travel of the respective vehicles in FIGS. 1 and 2 areindicated by arrows.

In the embodiment shown in FIG. 2, the milled material milled off by theworking drum 22 is discharged onto the loading surface 15 of thetransport vehicle 10 via a first permanently installed transportconveyor 11 of the transport conveyor device which transfers the milledmaterial 14 onto a second, slewable transport conveyor 12. As a resultof the speed of the transport conveyor 12 of the transport conveyordevice, the milled material 14 is not discharged immediately at the endof the transport conveyor 12, but the milled material follows aparabolic trajectory so that the point of impingement 16 on the loadingsurface 15 is located at a distance from the free end 13 of thetransport conveyor 12. The transport conveyor 12 may be slewed from aneutral position to the left or to the right via piston-cylinder units18 in order to be able to discharge the milled material 14 onto theloading surface 15 even when cornering or in the event of the transportvehicle 10 driving in an offset track, or in order to be able to bettermanoeuvre the milling machine when relocating it to a differentposition. In addition, the operator of the milling machine 1 a,1 b canadjust the elevation angle of the transport conveyor 12 by means of apiston-cylinder unit 20. The elevation angle has an influence on theparabolic trajectory of the milled material 14 and on the position ofthe point of impingement 16, as has the conveying speed of the transportconveyor 12.

The currently adjusted elevation angle about a horizontal axis 21 orslewing angle about a vertical axis 23 respectively, as well as thecurrent steering angle are reported to a detection and control system 24that may additionally comprise no less than one detector 26 whichcontinuously detects the position of the loading surface 15 and/or ofthe last or single transport conveyor 12 of the transport conveyordevice as seen in the direction of transport. Said detector 26 may bearranged either at the milling machine 1 a, 1 b, at the end facing thetransport conveyor 12, or at the free end 13 of the transport conveyor12.

The detection and control system 24 may be integrated into thecontroller 3 for the travelling, steering and milling operation operatedby the machine operator or may, as a minimum, be connected to the samein order to, should the need arise, also obtain data on the travelspeed, the distance travelled and/or a detected steering angle of themilling machine 1 a, 1 b and the conveying speed of the transportconveyor 12.

The controller 3 comprises a detection and control system 24 whichdetects the steering angle of the steering controller for the chassisand controls the slewing angle of the transport conveyor 12automatically in accordance with this parameter.

Alternatively, the steering angle of the steering controller and thedistance travelled may be detected, and the slewing angle of thetransport conveyor 12 may be controlled automatically in accordance withthese parameters. Additional detection of the distance travelled enablesexcessive alterations of the slewing angle to be avoided in case ofquick alterations of the steering angle. Alternatively, the travel speedmay also be detected, and the distance travelled may be computed fromthe travel speed.

An additional possibility consists in altering the slewing angle inaccordance with the steering angle only when a minimum speed has beenexceeded.

The slewing angle of the transport conveyor 12 therefore follows thesteering angle currently adjusted or adjusted on average over a specificdistance travelled, in which arrangement said steering angle may bedetected, for example, in that the current steering angle is permanentlydetected, for example, at the wheels or tracked travelling drive unitsof the front axle of the chassis or is taken directly from the steeringcontroller.

In this arrangement, the detection and control system 24 maycontinuously control the slewing angle of the transport conveyor 12automatically in such a way that in each steering situation duringforward travel or reverse travel, the slewable transport conveyor 12assumes a slewing angle computed and specified by the controller.

As a result, the operator of the milling machine does not need toconcern himself with continuously monitoring and, should the need arise,adjusting the slewing angle of the transport conveyor when cornering, beit in the milling operation or when relocating the machine to adifferent position. Rather, automatic control of the slewing anglereliably achieves for the transport conveyor 12 to essentially behavelike a trailing trailer attached to the milling machine when in forwardtravel. It is assumed in this arrangement that such fictitious traileris slewable about the first slewing axis 23, and the slewing angle thetrailer would assume when cornering in forward travel is used for bothforward travel and reverse travel as the adjustable specified slewingangle for the transport conveyor 12.

The fictitious trailer comprises a wheel axle which forms a centre ofrotation. For the purpose of the controller 3 or the detection andcontrol system 24 respectively computing the slewing angle, the positionof the centre of rotation can be selected freely preferably in the rangebetween one third and the entire length of the slewable transportconveyor 12, or between one third and the entire length up to the pointof impingement 16 on a loading surface 15 of the transport vehicle. In apreferred embodiment, the detection and control system 24 maycontinuously control the slewing angle of the transport conveyor 12automatically in such a way that the slewable transport conveyor 12assumes a slewing angle in each steering situation during forward travelor reverse travel in which the end of the transport conveyor 12, oralternatively the point of impingement 16 on the loading surface 15, isessentially guided along the centre line 34 of the track 32 previouslytravelled over or yet to be travelled over.

In accordance with an additional alternative, the end of the transportconveyor 12 may also be guided along an equidistant to the centre line34 of the track 32 previously travelled over or yet to be travelledover, namely, in the event that a transport vehicle 10 is moved next tothe track 32.

In addition, the detection and control system 24 may comprise a distancemeasurement device 40 which can be used to detect the distance to atransport vehicle 10 following in the conveying direction of thetransport conveyor 12. In this arrangement, the detection and controlsystem 24 may generate discernible, preferably visible start/stopsignals for the vehicle driver of the transport vehicle 10.

A distance range programmable or importable by means of teach-in may beenterable into the detection and control system 24, said distance rangebeing shorter than the maximum length of the loading surface 15 of theparticular transport vehicle 10. When leaving the specified distancerange, the start or stop signal may be indicated in accordance with thedistance measured.

FIG. 3 shows a milling machine 1 b in accordance with FIG. 1 corneringalong a centre line 34 of a track 32. During straight-ahead travel, thetransport conveyor 12 assumes the position shown in dashed lines. It isunderstood that, when a cornering procedure about a centre of rotation36 is initiated starting from such straight-ahead travel, the transportconveyor 12 would swing out widely if no slewing angle control wereperformed, and in so doing might, on the one hand, collide withobstacles on the roadside, for example, poles or traffic lights, duringrepositioning of the milling machine, or, if the slewing angle was notcorrected, might not be able to discharge onto a desired point ofimpingement 16 on the loading surface 15 of a transport vehicle duringthe milling operation.

The transport conveyor 12 illustrated by a solid line shows thesituation where an automatic control of the slewing angle is performedin which the free end of the transport conveyor 12 is guided along thecentre line 34. Computation of the slewing angle by the controller 3may, however, also be effected in such a way that the free end of thetransport conveyor 12 may also follow an equidistant to the centre line34 of the track 32 in order to be able to, for example, load a transportvehicle 10 travelling next to the track 32.

The detection and control system 24 may also locate the alterableposition of the loading surface 15 of the transport vehicle 10 and ofthe last or single transport conveyor 12 of the transport conveyordevice as seen in the direction of transport relative to the machineframe 2, and may continuously control positioning of the point ofimpingement 16 of the milled material 14 automatically via the elevationangle and/or the conveying speed of the transport conveyor device sothat the discharged milled material 14 impinges, as a minimum, withinthe loading surface 15. Alternatively, the alterable position of theloading surface 15 of the transport vehicle 10 may also be continuouslylocated relative to the last or single transport conveyor 12 as seen inthe direction of transport in order to perform the control operation.

The detection and control system 24 may detect the position of theloading surface 15 and/or of the last or single transport conveyor 12 asseen in the direction of transport continuously by means of animage-recording system 28 or a non-optical electronic positioning systemwhich supplies data for determining the position of the loading surface15 in relation to the machine frame 2 or to the last or single transportconveyor 12 as seen in the direction of transport. The informationprovided by the image-recording system 28 may be evaluated byimage-analysing methods known for themselves. One example of anon-optical electronic positioning system is a radio-frequencyidentification system (RFID) which additionally enables the possibilityof identifying a particular loading surface 15 of a particular transportvehicle 10.

When localizing the loading surface 15 by means of RFID, permanentlyinstalled RFID tags may be used at the transport vehicle 10 inparticular at the loading surface 15.

When localizing with Bluetooth sensor nodes as an additional non-opticallocalization method, sensor nodes distributed in space are used asmarkings and the signal field strength, which is dependent on thedistance, is measured.

It goes without saying that there is also the possibility to use acombination of different localization methods.

As a general rule, it is possible to use optical and quasi-optical(radio) measurement methods for length and angle, as well as differenttime measurement processes for time differences and propagation timedifferences.

The distance measurement may also be realized using the abovemeasurement methods or else with conventional measurement methods, forexample, by means of ultrasound.

The target position data may be determined by means of a teach-inprocedure in that the positions of the vehicles 1 a,1 b,10 are varied inaccordance with realistic situations and the parameters required foreach such situation, namely elevation angle and conveying speed of thetransport conveyor 12, are stored. In the same way, a loading programmemay also be created. In doing so, variations in control arising, forexample, during cornering may also be taken into account. In theprocess, the data read in by means of the reading operation may alsodifferentiate as to whether the transport vehicle 10 is driving on theleft or on the right next to the milling track 32 or in the millingtrack 32 of the milling machine 1 a, 1 b.

What is claimed is:
 1. An automotive milling machine, comprising: amachine frame with a longitudinal axis; a plurality of ground engagingunits configured to support the machine frame from a ground surface, atleast one of the ground engaging units being steerable in a steeringangle; working drum connected to the machine frame; a transport conveyorslewable sideways in a slewing angle relative to the machine frame aboutan essentially vertical first axis; at least one detector configured todetect at least one parameter, the at least one parameter including thesteering angle; and a controller connected to the at least one detectorto receive the at least one parameter, and configured to continuouslycontrol the slewing angle of the transport conveyor via associatedpiston-cylinder units and in accordance with the at least one parameter;wherein the controller is configured to continuously control the slewingangle of the transport conveyor such that the slewable transportconveyor assumes a slewing angle in each steering angle during forwardtravel which essentially corresponds to a slewing angle of alongitudinal axis of a slewable fictitious single-axle trailerarticulated at the first axis when in forward travel.
 2. The automotivemilling machine of claim 1, wherein: the controller is configured suchthat a location of the axle of the fictitious single-axle trailer isselectable in longitudinal direction.
 3. The automotive milling machineof claim 2, wherein: the controller is configured such that alongitudinal distance of the axle from the first axis is in a range offrom one-third to an entire length of the transport conveyor.
 4. Theautomotive milling machine of claim 3, wherein the longitudinal distanceof the axle from the first axis is in a range from 40% to 60% of theentire length of the transport conveyor.
 5. The automotive millingmachine of claim 2, wherein: the controller is configured such that alongitudinal distance of the axle from the first axis is in a range offrom one-third to an entire distance from the first axis to a point ofimpingement of milled material from the transport conveyor onto aloading surface of an associated transport vehicle.
 6. The automotivemilling machine of claim 5, wherein the longitudinal distance of theaxle from the first axis is in a range from 40% to 60% of the entiredistance from the first axis to the point of impingement.
 7. Anautomotive milling machine, comprising: a machine frame with alongitudinal axis, the machine frame having a front end and a rear endwith reference to a forward direction of travel; two front and two reartracked ground engaging units configured to support the machine framefrom a ground surface, the front and the rear tracked ground engagingunits being steerable in steering angles; a working drum connected tothe machine frame and located in a longitudinal direction between thefront and rear tracked ground engaging units; a plurality of liftingcolumns for adjusting a height of the machine frame and the working drumrelative to the ground surface, the machine frame being supported fromeach of the front and rear tracked ground engaging units by one of thelifting columns; a transport conveyor extending forward from the frontend of the machine frame and slewable sideways in a slewing anglerelative to the machine frame about an essentially vertical first axis;at least one detector configured to detect at least one parameter, theat least one parameter including at least one of the steering angles ofthe tracked ground engaging units; and a controller connected to the atleast one detector to receive the at least one parameter, and configuredto continuously control the slewing angle of the transport conveyor viaassociated piston-cylinder units and in accordance with the at least oneparameter, wherein the controller is configured to automatically controlthe slewing angle of the transport conveyor such that during forwardtravel an end of the transport conveyor is essentially guided along acenter line, or at a constant spacing from the center line, of a trackto be travelled over by the milling machine.
 8. The automotive millingmachine of claim 7, wherein: the controller is configured such thatduring forward travel the transport conveyor is guided along a path tobe travelled over by the milling machine.
 9. The automotive millingmachine of claim 7, wherein the at least one parameter further includesa distance travelled by the milling machine.
 10. The automotive millingmachine of claim 7, wherein the at least one parameter further includesa travel speed of the milling machine.
 11. The automotive millingmachine of claim 7, wherein: the controller is configured toautomatically control the slewing angle of the transport conveyor suchthat during forward travel an end of the transport conveyor is guided toremain in a track to be travelled over by the milling machine.
 12. Theautomotive milling machine of claim 7, wherein: the transport conveyoris slewable in an elevation angle about a second axis orthogonal to thefirst axis; the transport conveyor is configured to discharge milledmaterial at a conveying speed onto a point of impingement on a loadingsurface of a transport vehicle travelling ahead of the milling machine;and the controller configured to determine a position of the loadingsurface relative to the transport conveyor and to control at least theslewing angle so as to maintain the point of impingement on the loadingsurface.
 13. The automotive milling machine of claim 12, wherein: thecontroller is further configured to control the elevation angle so as tomaintain the point of impingement on the loading surface.
 14. Theautomotive milling machine of claim 12, wherein: the controller isfurther configured to control the conveying speed so as to maintain thepoint of impingement on the loading surface.
 15. The automotive millingmachine of claim 12, wherein the controller is configured to maintainthe point of impingement along a longitudinal median plane of theloading surface.
 16. The automotive milling machine of claim 12, whereinthe controller is configured to maintain the point of impingement in atrack of the milling machine.
 17. The automotive milling machine ofclaim 12, wherein the at least one detector is selected from the groupconsisting of: a steering detector configured to detect the steeringangle of at least one of the tracked ground engaging units; a slewingdetector configured to detect the slewing angle of the transportconveyor; an elevation detector configured to detect the elevation angleof the transport conveyor; and a conveying speed detector configured todetect the conveying speed of the transport conveyor.
 18. The automotivemilling machine of claim 7, wherein the at least one detector furthercomprises: a distance detector configured to detect a distance travelledby the milling machine.
 19. The automotive milling machine of claim 7,wherein the at least one detector further comprises: a speed detectorconfigured to detect a travel speed of the milling machine.
 20. Themilling machine of claim 7, wherein the at least one detector comprises:a distance measuring detector configured to detect a distance from thedischarge conveyor to a transport vehicle; and wherein the controller isconfigured to generate start and stop signals for the transport vehiclediscernible by a vehicle driver of the transport vehicle.
 21. Themilling machine of claim 20, wherein: the controller is configured suchthat a specified distance range may be entered into the controller, thedistance range being less than a maximum length of a loading surface ofthe transport vehicle; and the controller is configured such that thestart and stop signals are generated in accordance with the distancefrom the discharge conveyor to the transport vehicle and in accordancewith the specified distance range.
 22. The milling machine of claim 7,wherein the at least one detector comprises: a distance measuringdetector configured to detect a distance from the machine frame to atransport vehicle; and wherein the controller is configured to generatestart and stop signals for the transport vehicle discernible by avehicle driver of the transport vehicle.
 23. The milling machine ofclaim 22, wherein: the controller is configured such that a specifieddistance range may be entered into the controller, the distance rangebeing less than a maximum length of a loading surface of the transportvehicle; and the controller is configured such that the start and stopsignals are generated in accordance with the distance from the machineframe to the transport vehicle and in accordance with the specifieddistance range.
 24. The milling machine of claim 7, wherein the at leastone detector is configured to detect a relative position between thedischarge conveyor and the transport vehicle.
 25. The milling machine ofclaim 7, wherein the at least one detector is configured to detect arelative position between the machine frame and the transport vehicle.26. An automotive milling machine, comprising: a machine frame with alongitudinal axis, the machine frame having a front end and a rear endwith reference to a forward direction of travel; two front wheels andtwo rear wheels configured to support the machine frame from a groundsurface, the front wheels being steerable in steering angles; a workingdrum connected to the machine frame laterally between the two rearwheels; two rear lifting columns for adjusting a height of the machineframe and the working drum relative to the ground surface, the machineframe being supported from each of the rear wheels by one of the liftingcolumns; a transport conveyor extending rearward from the rear end ofthe machine frame and slewable sideways in a slewing angle relative tothe machine frame about an essentially vertical first axis; at least onedetector configured to detect at least one parameter, the at least oneparameter including the steering angle of at least one of the frontwheels; and a controller connected to the at least one detector toreceive the at least one parameter, and configured to control theslewing angle of the transport conveyor in accordance with the at leastone parameter, wherein the controller is configured to automaticallycontrol the slewing angle of the transport conveyor such that duringforward travel an end of the transport conveyor is essentially guidedalong a center line, or at a constant spacing from the center line, of atrack previously travelled over by the milling machine.
 27. Theautomotive milling machine of claim 26, wherein: the controller isconfigured such that during forward travel the transport conveyor isguided along a path previously travelled over by the milling machine.28. The automotive milling machine of claim 26, wherein the at least oneparameter further includes a distance travelled by the milling machine.29. The automotive milling machine of claim 26, wherein the at least oneparameter further includes a travel speed of the milling machine. 30.The automotive milling machine of claim 26, wherein: the controller isconfigured to automatically control the slewing angle of the transportconveyor such that during forward travel an end of the transportconveyor is guided to remain in a track previously travelled over by themilling machine.
 31. The automotive milling machine of claim 26,wherein: the transport conveyor is pivotable in an elevation angle abouta second axis orthogonal to the first axis; the transport conveyor isconfigured to discharge milled material at a conveying speed onto apoint of impingement on a loading surface of a transport vehicletravelling behind the milling machine; and the controller is configuredto determine a position of the loading surface relative to the transportconveyor and to control at least the slewing angle so as to maintain thepoint of impingement on the loading surface.
 32. The automotive millingmachine of claim 31, wherein the controller is further configured tocontrol the elevation angle so as to maintain the point of impingementon the loading surface.
 33. The automotive milling machine of claim 31,wherein the controller is further configured to control the conveyingspeed so as to maintain the point of impingement on the loading surface.34. The automotive milling machine of claim 31, wherein the controlleris configured to maintain the point of impingement along a longitudinalmedian plane of the loading surface.
 35. The automotive milling machineof claim 31, wherein the controller is configured to maintain the pointof impingement along a track of the milling machine.
 36. The automotivemilling machine of claim 31, wherein the at least one detector includesat least one detector selected from the group consisting of: a steeringdetector configured to detect the steering angle of the at least one ofthe front wheels; a slewing detector configured to detect the slewingangle of the transport conveyor; an elevation detector configured todetect the elevation angle of the transport conveyor; and a conveyingspeed detector configured to detect the conveying speed of the transportconveyor.
 37. The automotive milling machine of claim 26, wherein the atleast one detector further comprises: a distance detector configured todetect a distance travelled by the milling machine.
 38. The automotivemilling machine of claim 26, wherein the at least one detector furthercomprises: a speed detector configured to detect a travel speed of themilling machine.
 39. The milling machine of claim 26, wherein the atleast one detector comprises: a distance measuring detector configuredto detect a distance from the discharge conveyor to a transport vehicle;and wherein the controller is configured to generate start and stopsignals for the transport vehicle discernible by a vehicle driver of thetransport vehicle.
 40. The milling machine of claim 39, wherein: thecontroller is configured such that a specified distance range may beentered into the controller, the distance range being less than amaximum length of a loading surface of the transport vehicle; and thecontroller is configured such that the start and stop signals aregenerated in accordance with the distance from the discharge conveyor tothe transport vehicle and in accordance with the specified distancerange.
 41. The milling machine of claim 26, wherein the at least onedetector comprises: a distance measuring detector configured to detect adistance from the machine frame to a transport vehicle; and wherein thecontroller is configured to generate start and stop signals for thetransport vehicle discernible by a vehicle driver of the transportvehicle.
 42. The milling machine of claim 41, wherein: the controller isconfigured such that a specified distance range may be entered into thecontroller, the distance range being less than a maximum length of aloading surface of the transport vehicle; and the controller isconfigured such that the start and stop signals are generated inaccordance with the distance from the machine frame to the transportvehicle and in accordance with the specified distance range.
 43. Themilling machine of claim 26, wherein the at least one detector isconfigured to detect a relative position between the discharge conveyorand the transport vehicle.
 44. The milling machine of claim 26, whereinthe at least one detector is configured to detect a relative positionbetween the machine frame and the transport vehicle.